NO. 6 



CATERPILLAR AND BUTTERFLY — SNODGRASS 



lepidopterous family, but taxonomists now assign them to a separate 

 order, the Zeugloptera (Chapman, 1917), which Hinton (1946) con- 

 tends is more primitive even than the Trichoptera. However, what- 

 ever may be the correct classification of the micropterygids, their 



D 



Fig. 3. — Evolution of the lepidopterous proboscis, and the sucking pump 

 (A,B,C, from Tillyard, 1923). 



A, Maxilla of Micropteryx auruncella. B, Maxilla of Eriocrania semiperpurella. 

 C, Maxilla of Mnesarchaea paracosma. D, base of a typical, fully developed 

 lepidopterous maxilla. E, Head of Sanninoidea exitiosa. F, Section of head of 

 sphinx moth, diagrammatic, showing the sucking pump and its muscles. 



ancestors must have had some relation to the ancestors of the Lepidop- 

 tera, and their modern mouth parts may be taken as an approximate 

 example of the feeding organs of the lepidopterous progenitors. The 

 adult micropterygids have well-developed functional jawlike mandi- 

 bles. The maxillae (fig. 3 A) are of generalized structure, each organ 



